The GTA V torture scene is such blatant satire and criticism of the practice of government-sanctioned torture, I don't know how anyone could possibly think it's in there "just for fun". It doesn't ask the player to decide whether it's a good or bad practice. It is a completely anti-torture, pro-human rights statement.
Observations in spoiler text:
1 - The prisoner is a completely innocent person. Of course the player should be sympathetic to him.
2 - The perpetrators are shallow government scumbags who just want to advance their careers. They even let their buddy come in and abuse the prisoner for fun. These guys are not heroes protecting freedom.
3 - The results of the torture lead to useless information and a very bad outcome: the killing of a philanthropist (a good guy) based primarily on superficial racial profiling.
4 - Afterwards, during the drive to the airport, Trevor consoles the victim and lectures about the evils of government agencies run amok.
So can we stop pretending the intent of the torture scene is somehow unclear?